Please please please maybe consider looking into support for Hybrid Renderer V2 in DOTS!
The TL;DR of how to implement it is here https://forum.unity.com/threads/hybrid-renderer-v2-0-4-0.847546/page-3#post-5743939 .
I'm sure its not that easy but I think you might be pretty close already considering GPU Instancing is supported.
P.S. I love this asset, top notch quality!